Thermostat.



E. M. PETERSOHN. THERMOSTAT. APPLICATION FILED MAR. 17. 1915.

1,175,010. Patented Mm. 1-1, 1911;.

EMIL M. IPETERSOHN, OF CHICAGO, ILLINOIS.

'rnnnivros'ra'r.

Specification of Letters Patent.

Patented Mar. 14, 1916.

Application filed March 17, 1915. Serial No. 14,908.

To all whom it may concern:

Be it known that I, EMIL M. PETERSOHN, a citizen of the United States, residing at 2533 Ems street, in the city of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Thermostats, of which the following is a specification.

My invention relates to improvements in thermostats and particularly to devices of that class which are utilized principally in fire alarm and similar systems.

The objects of my invention are to so construct a device of this character that it will positively and automatically operate when the heat to which it is exposed reaches a certain predetermined temperature, to so arrange the parts thereof that it may be easily and quickly dismounted and assembled and to provide adjustment so that the device may be regulated and set to operate at any desired temperature.

I accomplish the above and other objects as fully set forth and described in the following specification and as particularly pointed out in the appended claims, reference being had to the accompanying drawings in which a preferred embodiment or adaptation of my invention is illustrated.

In the drawings: Figure 1 is a top plan view of the improved thermostat, a fragment of the top cover being broken away to expose the interior mechanism. Fig. 2 is a vertical central section through the device on dotted line 2. 2. Fig. 1, looking in the direction of the arrows W. Fig. 3 is a fragmentary. edge view to show the adjusting mechanism. Fig. 1 is a bottom plan view of the improved device. Fig. 5 is a detached enlarged view of the adjusting cam. Fig. 6 is a reduced top plan view of the improved thermostat with a diagram of an electric circuit, an alarm or bell and a battery.

In referring to the drawings in detail like numerals designate corresponding and similar parts in the preferred embodiment of v my invention shown therein.

The case or container of my improved device comprises two members, a lower or base member having a bottom, 1, provided with a plurality of perforations, 2, and an annue lar upwardly extending flange, 3, forming the circular side of the case, and an upper or top member having a flat top, 4:, and a depending flange, 5, adapted to fit around the top portion of the flange, 3, as shown in Figs. 2 and 3. e

A thermostatic element, 6, is located in the lower or base member and preferably with its circular lower edge lying against the inner wall of the base member at the juncture of the bottom, 1, and flange, 3, as shown in Fig. 2. The thermostatic element is constructed of suitable heat expanding metal andI prefer to make it in the hollow conical form shown, and to provide it at its apex with a suitable thickened or enlarged portion, 7, having a central vertical aperture in which an adjusting screw, 8, is fitted. To the underside of the cover I suitably attach a pair of levers, 9, and 10, the shorter lever, 9, being pivoted to a nearly center depending post, 11, by a pivot screw or bolt, 12, and being provided with acomparatively short arm, 13, which extends vertically above the adjusting screw, 8, substantially as shown in Fig. 2. The longer lever, 10, is pivoted at one end to a post, 14, depending from the cover and located-near the flanged edge "thereof, and said long lever, 10, extends approximately parallel with the short lever, 9, and nearly to the opposite side of the cover as shown in Fig. 1, and said levers are pivotally connected to each other by a transverse connecting bar, 15, located a short distance inwardly from the post, 1 1. To

keep the two levers separated from each other a separating ring, 16, is placed on the bar between them. The two levers are normally maintained in their horizontal inoperativeposition by a" flat spring, 17, which has its outer extremity suitably fastened to the cover. a

One of the electric terminals, 18, is rotatably fitted through an opening in the flange, 3, and .a cam, 19, formed substantially as shown in Fig. 5, is mounted on its inner end and arranged vertically beneath the free end of the longer lever, 10. A disk, 20, is attached to the outside of the ease and is provided with a series of graduations, 21, for

indicating the temperature at which the device is to be operated, and. a pointer, 22, is attached to the outer end of the terminal,18, which is adapted to be turned toregister with any one of the series of graduations, as shown in Fig. 3. The terminal, -18, is suitably insulated from the case by a fiber bushing, 3, and an electric wire, 24., is connected thereto. The other electric terminal, 25, is rigidly connected to' the case at one side of the rotatable or adjustable terminal, 18, and is not insulated therefrom.

Referring to Fig. 6, the wire, 24, extends from-the terminal, 18, and connects to one a pole of a battery, 26, andanother wire, 27,

extends from the-terminal, 25, and connects to an alarm or bell, 28, which is also connected by a wire, 29, to the battery to' form a circuit. The two oppositely lo'cated strips, 30, shown in Figs. 1, 3 and 4, provide con venient means'for attaching the thermostat to any suitable point.

The operation of the embodiment of my invention shown in the accompanying draw ings is approximately as follows: The pointer having been adjusted or set to a desired temperature, and the atmosphere in the room in which the thermostat is located having reached that temperature, the heat passing through the perforations, 2, in the bottom impinges against and expands the hollow conical thermostatic element, which owing to the fact thatits outer circular edge is rigidly held in the lower member of the case causes the apex thereof to move upward and carry with it the adjusting screw, 8. The adjusting screw, 8, in turn presses the short arm, 13, upwardly thereby depressing the lever, 9, and through the connecting bar, 15, also depressing the lever, 10, into contact with the cam, 19, and completing an electric circuit which rings the alarm. The posts to which the levers are pivoted and the connection between the levers are so relatively arranged and located that .a comparatively my invention into effect which is capable of a wide range of variation and modification without departing from the spirit of my invention, I therefore do not wish to be limited tothe details of construction herein set.

forth, but desire to avail myself of such variations and modifications as fairly fall within the scope of the appended claims.

I What I claim as my invention and desire to secure by Letters Patent is:

1. In a device of the class described, a case, two electric terminals mounted in said case, one of which is insulated therefrom andv is adjustable, acam on said. adjustable terminal, a hollow conical thermostatic element within the said case, and lever mechanism also mounted within the case and having a part thereof projecting in proximity to the apex of the conical thermostatic element and a part thereof projecting in proximity to the cam on one of the electric terminals.

2. In a device of the class described, a case, two electric terminals mounted in said case, one of which is insulated therefrom and is adjustable, a cam on the inner end of said adjustable terminal, an indicating pointer on the outer -end,'of said adjustable terminal, a graduated temperature disk arranged relatively to-the pointer, a hollow conical thermostatic element within said case, and lever mechanism also 'mounted within the case and having a part thereof projecting in proximity to the apex of the conical thermostatic element and a part thereof projecting in proximity to the cam on one ofthe electric terminals.

3. In a device of the class described, a'

case having a base member and a cover mem ber, a plurality of levers pivoted to the cover member, a hollow conical element expansible' by heat fitted within the base member, an adjusting screw vertically arranged in the apex of the conical element and adapted to 'press'against one of said levers and electric terminals attached to the side of the base, one being insulated therefrom, and being adapted to be electrically connected to the other terminal through the expansion of the conical element.

In testimony whereof I have hereunto af- -fixed my name in the presenceof two witnesses.

I 1 EMIL M. PETERSOHN. Witnesses:

ROBT. KLoTz, A G. GUENTHER. 

